Grouping objects by similarity using k-means
  K-means++
  Hard versus soft clustering
  Using the elbow method to find the optimal number of clusters
  Quantifying the quality of clustering via silhouette plots
Organizing clusters as a hierarchical tree
  Performing hierarchical clustering on a distance matrix
  Attaching dendrograms to a heat map
  Applying agglomerative clustering via scikit-learn
Locating regions of high density via DBSCAN
Summary